Ivory and bone are both materials that can be used to make a variety of objects, from jewelry to furniture. However, they are not the same material. Ivory is a hard, white material that is derived from the tusks of elephants and other animals. Bone is a hard, white material that is derived from the bones of animals. While these two materials can look similar, there are a few key differences between them that can help you to tell them apart.
One of the most obvious differences between ivory and bone is their color. Ivory is typically a pure white, while bone is usually a creamier white. Additionally, ivory has a more lustrous finish than bone. This is because ivory is made of a dense, hard material that does not easily absorb light. Bone, on the other hand, is made of a less dense material that absorbs light more easily. As a result, bone has a duller finish than ivory.
Another difference between ivory and bone is their texture. Ivory is a smooth, hard material that does not have any pores. Bone, on the other hand, is a porous material that has many small holes. This difference in texture can be felt when you touch the two materials. Ivory feels smooth and slick, while bone feels rough and bumpy. This is because the pores in bone trap air, which creates a rough surface. Additionally, ivory is a harder material than bone. This means that it is more difficult to scratch or dent ivory than bone.
Physical Examination: Surface Appearance
Surface Texture:
Ivory exhibits a smooth, polished surface with a silky feel. In contrast, bone has a rougher texture and may have tiny pores or grooves due to its porous nature. The smoothness of ivory is attributed to its compact structure, while bone’s porosity results in a more uneven surface.
Grain Pattern:
Ivory exhibits a distinctive “cross-hatched” or “engine-turned” grain pattern, which is particularly visible on curved surfaces. This pattern arises from the arrangement of microscopic fibers within the ivory. Bone, on the other hand, lacks this characteristic grain and typically has a more uniform appearance.
Color and Translucence:
Ivory varies in color from creamy white to yellowish-brown, while bone is typically a dull white or ivory color. Ivory is translucent to some degree, allowing light to pass through it, particularly in thin sections. Bone is opaque, blocking the passage of light.
| Property | Ivory | Bone |
|---|---|---|
| Surface Texture | Smooth, silky | Rough, porous |
| Grain Pattern | Cross-hatched | Uniform |
| Color | Creamy white to yellowish-brown | Dull white to ivory |
| Translucence | Translucent | Opaque |
Translucent Test: Sunlight or Artificial Light
The translucency test involves holding the object up to a light source to observe how much light passes through it. This test is frequently used to distinguish ivory from bone, as ivory is typically more translucent than bone.
Sunlight Translucency Test
Natural light provides optimal conditions for the translucent test. Hold the object up to a window or other source of sunlight. If the object is ivory, light should pass through it, creating a soft, warm glow. On the other hand, bone tends to be more opaque, allowing less light to pass through.
Artificial Light Translucency Test
If natural light is not available, an artificial light source can also be used for this test. Position the object between a lamp or flashlight and a flat surface. Again, if the object is ivory, light should easily penetrate it, resulting in a noticeable glow. Bone, on the other hand, may appear darker and absorb more light.
| Material | Translucency | Light Penetration |
|---|---|---|
| Ivory | Translucent | Soft, warm glow |
| Bone | Opaque | Limited light penetration |
Scratch Test: Texture and Brittleness
A simple scratch test can help you distinguish between ivory and bone. Ivory is a hard material, while bone is softer. To perform the test, use a sharp object, such as a knife or needle, to gently scratch the surface of the object. If the material scratches easily, it is likely bone. If the material is resistant to scratching, it is likely ivory.
Texture and Brittleness
Ivory and bone may have different textures and brittleness that can aid you in differentiating between the two. Ivory tends to have a smoother, more polished surface than bone. It is also more flexible and less brittle than bone. When you bend or twist a piece of ivory, it will likely return to its original shape without breaking. Bone, on the other hand, is more brittle and may snap or crack if you apply too much force.
| Property | Ivory | Bone |
|---|---|---|
| Texture | Smooth, polished | Rougher, less polished |
| Brittleness | Flexible, less brittle | Brittle, more likely to break or crack |
Thermal Conductivity: Heat Resistance
Thermal conductivity measures how well a material conducts heat. Generally, ivory is a better thermal conductor than bone. This means that ivory will feel warmer to the touch than bone when held in the hand. To test this property, place a small piece of ivory and a small piece of bone on a cold surface. The ivory will warm up faster than the bone, indicating its higher thermal conductivity.
In addition to its high thermal conductivity, ivory also has low heat resistance. This means that ivory does not retain heat well, and it will cool down quickly once it is removed from a heat source. In contrast, bone has higher heat resistance, meaning it takes longer to heat up and cool down. This difference in heat resistance can be used to distinguish between ivory and bone.
To test the heat resistance of a material, heat a small piece of ivory and bone to the same temperature. Then remove the samples from the heat source and place them on a cool surface. The ivory will cool down faster than the bone, indicating its lower heat resistance.
Measuring Thermal Conductivity
The thermal conductivity of a material can be measured using a variety of techniques. One common technique is to use a heat flow meter. A heat flow meter measures the amount of heat that flows through a material when a temperature difference is applied across it.
The thermal conductivity of a material can also be estimated using empirical formulas. These formulas are based on the material’s composition and structure. For example, the following formula can be used to estimate the thermal conductivity of ivory:
“`
k = 0.024 W/m-K
“`
Where:
| k | Thermal conductivity | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| W | Watts | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| m | Meters | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| K | Degrees Kelvin
Color and Grain Patterns: Natural VariationsIvory and bone are both natural materials with distinct color and grain patterns. Ivory is typically a creamy white color, while bone can range from white to yellow or brown. The grain patterns of ivory and bone also differ, with ivory having a finer and more uniform grain than bone. One way to differentiate ivory from bone is to look at the grain pattern. Ivory has a fine, even grain that is often visible to the naked eye. Bone, on the other hand, has a coarser grain that is not as easily visible. The direction of the grain can also help to distinguish between ivory and bone. Ivory’s grain runs parallel to the length of the tusk, while bone’s grain runs in a more random pattern. This difference in grain direction can be seen when the material is cut or carved. Variations in ColorThe color of ivory and bone can vary depending on a number of factors, including the age and health of the animal, the environment in which it lived, and the way in which it was processed. Ivory from older animals tends to be darker and more yellowed than ivory from younger animals. Ivory from animals that lived in harsh environments may also be darker and more discolored. Chemical CompositionIvory and bone are both composed of calcium phosphate, but they differ in their chemical composition. Ivory contains more calcium carbonate than bone, which gives it a harder and more durable surface. Bone, on the other hand, contains more collagen than ivory, which gives it a more flexible and resilient structure.
Chemical Tests: Reaction to Acids and BasesAcids and bases can react with ivory and bone in different ways, providing a means of distinguishing between the two materials. These reactions can be used for both qualitative and quantitative analysis. Acid TestWhen ivory is exposed to an acid, such as hydrochloric acid, it will dissolve and release carbon dioxide gas. This reaction can be used to identify ivory by observing the effervescence of the solution. Bone, on the other hand, will not react with acids in this way. Base TestWhen ivory is exposed to a base, such as sodium hydroxide, it will react to form a salt and release ammonia gas. This reaction can be used to identify ivory by observing the release of ammonia gas and the formation of a salt precipitate. Qualitative AnalysisThe acid and base tests can be used to qualitatively distinguish between ivory and bone. Ivory will react with both acids and bases, while bone will only react with acids. Quantitative AnalysisThe acid and base tests can also be used to quantitatively determine the amount of ivory present in a sample. The amount of carbon dioxide gas released in the acid test or the amount of ammonia gas released in the base test can be used to calculate the amount of ivory present.
Microscopy: Examination of MicrostructuresExamining the microstructures of ivory and bone under a microscope can provide valuable clues for differentiation. Ivory exhibits a distinctive cross-hatched pattern known as the Schreger lines, which result from the arrangement of mineral crystals within the dentin. These lines are absent in bone, which instead shows a more haphazard and irregular pattern of mineral crystals. In addition, ivory exhibits smaller and more closely packed dentinal tubules compared to bone. Schreger LinesThe presence of Schreger lines is a key indicator of ivory. These lines are visible in both transmitted and reflected light, and they can be used to distinguish ivory from bone even in small fragments. Dentinal TubulesThe dentinal tubules in ivory are typically smaller and more closely packed than those in bone. This difference can be observed under a microscope, and it can help to distinguish between the two materials.
X-ray Imaging: Internal Structure AnalysisX-ray imaging is a non-destructive technique that allows researchers to visualize the internal structure of objects. When X-rays pass through an object, they are absorbed and scattered by the material. The amount of absorption and scattering depends on the density and atomic composition of the material. This information can be used to create an image of the object’s internal structure. X-ray imaging is used to identify ivory from other materials, such as bone. Ivory is denser than bone, so it absorbs more X-rays. This results in a darker image on an X-ray. Additionally, the internal structure of ivory is different from the internal structure of bone. Ivory has a more uniform structure, while bone has a more complex structure with Haversian canals and lacunae. The following table summarizes the differences between ivory and bone in X-ray images:
X-ray imaging is a valuable tool for identifying ivory from other materials and providing information about the object’s age, origin, and manufacturing techniques. Professional Appraisal: Expert EvaluationSeeking professional appraisal from a qualified jeweler or antique dealer is highly recommended for accurate identification. Expert evaluators possess the knowledge, experience, and tools to examine the item thoroughly, assessing its characteristics and identifying its true nature as either ivory or bone. The following parameters are typically assessed by professional appraisers to distinguish ivory from bone: Visual InspectionExperts closely examine the surface texture, grain pattern, and color of the material. Ivory exhibits a distinctive cross-hatched grain pattern, while bone has a more porous and irregular texture. Ivory is typically whiter and brighter, while bone tends to have a yellowish or creamy hue. Hardness TestAppraisers gently scratch the surface of the object. Ivory is harder than bone, and the scratch will be less pronounced on ivory. Specific Gravity TestThe specific gravity of ivory is higher than that of bone, so experts weigh the object in air and then in water to determine its density. Ivory sinks faster in water than bone. Fluorescence TestUnder ultraviolet light, ivory fluoresces a distinctive blue-white color, while bone does not fluoresce or emits a different color. Burn TestAs a last resort, appraisers may conduct a burn test. When burned, ivory emits a faint, sweet odor, while bone produces a pungent, burnt smell.
Ethical Considerations: Avoiding Misidentification Misidentification: Consequences and ResponsibilitiesIncorrectly identifying ivory as bone can have significant ethical and legal consequences, potentially leading to the trade in illegal ivory and the endangerment of elephants. Collectors, dealers, and consumers have a responsibility to ensure accurate identification to prevent contributing to these harmful practices. Understanding the Physical DifferencesIdentifying ivory from bone requires careful examination of specific physical characteristics. Ivory, derived from the tusks of elephants, is composed of dentin, a dense, mineralized tissue. Bone, on the other hand, is a composite material consisting of collagen fibers and hydroxyapatite crystals. Key Distinguishing FeaturesHere are some key differences between ivory and bone:
Ethical Guidelines for Collectors and DealersDealers and collectors should adhere to ethical guidelines to ensure the responsible handling of ivory and bone items. Documenting and Verifying OriginMaintain accurate records of the origin and purchase history of ivory and bone items, including documentation of legality and sustainability. |
